Question

5 litre of a solution contains 25 mg of `CaCO_(3)`. What is its concentration in ppm? (mol.wt of `CaCO_(3)` is 100)
A. 25
B. 1
C. 5
D. 2500

Answer 1

Correct Answer - C
5 lit. water `=5xx10^(3)g=5xx10^(6)` mg
`5xx10^(6)` mg water contains 25 mg `CaCO_(3)`
`:. 10^(6)` mg water contains 5 mg `CaCO_(3)`
`:.` Concentration is 5 ppm.
For `4g=(2xx22.4xx4)/16=11.2 L` of `O_(2)` is required.